1. Technical Field Disclosure
The embodiment of the present disclosure relates generally to a method, and, more particularly, to a method for processing images.
2. Description of Related Art
In recent years, liquid crystal displays (LCDs) have gradually replaced conventional cathode-ray tube (CRT) displays as a result of their advantages, such as their light weight, compact size, low power-consumption, and minimal radiation emission. LCDs employ a maintenance type of display technique, characterized in that the current image brightness is maintained until the next image is refreshed. That is, the current image is maintained for as long as necessary until a new image is required.
Due to the persistence of vision experienced by human eyes, the longer the current image is maintained by an LCD, the longer it is perceived by the retina. In addition, when viewing an object, human eyes follow the motion trajectory of the object so as to clearly observe the moving object, regardless of whether the object moves linearly or non-linearly. Combined together, these features lead to a phenomenon called afterimage, in which the periphery of a moving object is perceived to be blurred due to the overlapping of the previous image persisted on the retina and the current image.
Blurring effect refers to the phenomenon caused by the combination of the image-maintaining characteristics of the LCD and the vision persistence of human eyes that results in the overlapping of adjacent images. For example, when the image refreshes, the previous image resulted from the vision persistence overlaps with the current image, thereby causing the blurring effect of the object which may cause discomfort to the viewer.
The most commonly employed motion estimation techniques are bi-directional motion estimation and uni-directional motion estimation. Bi-directional motion estimation is different from conventional motion estimation in that it takes the aspect of a block of an interpolated frame and finds an optimal comparing block by symmetrically searching the search range of two adjacent frames, and then obtains a motion trajectory passing through the block of the interpolated frame as the motion vector. On the other hand, uni-directional motion estimation uses the current frame as the starting point to perform motion estimation and image compensation.
However, bi-directional motion estimation may result in estimation error; for example, when a simple or plain background is present behind an object, bi-directional motion estimation may erroneously detect the background value. One disadvantage of uni-directional motion estimation is that it has a motion blank region or motion overlapping region which greatly degrades image quality.